Stream Piracy 



75 



the oval hill, the course swings around toward the south. From this 

 bend, toward the north, east of the hill is a broad valley running down 

 to the main east fork, but without a stream in it. This streamless 

 valley serves to isolate the oval hill from the main valley wall on the 

 east as does the east branch of the west fork from the valley wall on 

 the south. 



In figures 1, 2 and 3, the attempt is made to illustrate what is be- 

 lieved to be the drainage development of this hill and the surrounding 



5ca|e, '. °° - i^F ^ CPer-ry-^anent sTr-cum CZD 



Contour inter' vq) , 2. ft. Legendilnrer-mittent stneum 



Datum , nnean sea level. iRehef 



Fig. 3. Present drainage showing the progress of piracy as begun and illustrated 

 in figure 2. 



valleys. Figure 1 shows the approximate drainage relations before the 

 piracy began. The west fork has not bifurcated; a branch runs down 

 to the east of the oval-shaped hill (now only a point running out from 

 the south wall) , joining the east fork. Figure 2 tells substantially the 

 same story, except that there is a gully cutting off from the west fork 

 which in time will behead the branch of the east fork. Figure 3 shows 

 present drainage relations, the gully having completely separated the 

 hill from the south wall and beheaded the other branch. 



